1. Field of the Invention
The present invention relates to an endoscope apparatus suitable for portable use.
2. Related Art Statement
Endoscopes have been widely used in the medical field and the industrial field. An object to be diagnosed or examined by the endoscopes is located in the interior of a living body, a plant or the like. Thus, the endoscopes must be provided with illumination means for supplying illumination light thereto.
An ordinary endoscope apparatus comprises an endoscope and an external light source. A lamp is disposed in the light source device and the illumination light emitted from the lamp is guided to a light guide fiber disposed in the endoscope. Then, the illumination light is transmitted through the light guide fiber, emerges from an illumination window disposed on the distal end of an insertion tube and illuminates an object to be examined.
The light source device ordinarily causes the lamp disposed therein to emit light using power supplied form a wall outlet. On the other hand, Japanese Unexamined Patent Publication No. 9-224906, for example, discloses an endoscope using a battery or the like as the power supply.
In the endoscope, a battery-powered light source is detachably mounted on a control section of the endoscope. Since the endoscope having the detachably mounted battery-powered light source can be easily carried as well as used in a location where a wall outlet is not readily available, this type of endoscope is suitable for emergency use and the like.
In the battery-powered light source which uses the battery as the power supply for the light source device of the endoscope, however, the lamp is turned on and off by a switch connected to the main body of the light source. Since the switch is generally either a small rotary type knob switch or a push type button switch, it is difficult to discriminate whether the switch is turned on or off at a glance, whereby it would be easy to forget to turn off the switch.
Further, when the endoscope is held by being suspended from an endoscope hanger, the distal end of the endoscope points downward. As a result, when the endoscope is suspended from the hanger with its lamp turned on, it is possible that the endoscope would be kept in that state for an unnecessarily long period of time if the user is unaware of the illuminating light being emitted from the distal end of the endoscope. Therefore, the battery would become unusable due to battery exhaustion.
A further disadvantage is encountered if the operator unintentionally turns on the light when preparing the endoscope for use or when washing the endoscope and causing the battery to go dead and therefore unusable.